How did you manage to get the exact measurements for the object in question? Did you use a pair of calipers? Would that even work?
That would make sense. But what if I'm looking to make something exact for printing reasons or to match the spec for customer requirements.
You can always measure it if you have one or look for blue prints/spec sheet.
Usually if you're modeling something for a company, they will send you exact measurements and you won't need to measure things for yourself. There are also often blueprints or spec sheets you can find online like Dwayne mentioned. In this case I just used a tape measure since I wasn't worried about being totally exact 😄